The present invention relates to a high humidity gas turbine equipment, in which a turbine is driven by combustion gas obtained from a humidified air and fuel drive.
High humidity gas turbine equipment uses a humidifier to humidify air compressed by a compressor to feed the humidified air to a combustor to generate combustion gas to drive a turbine. When a compressed air being supplied to a combustor is humidified in this manner, combustion gas are increased in flow rate and in specific heat capacity, so that it is possible to increase a turbine output as compared with the case where a compressed air is not humidified. Also, when an amount of heat required for generating electrical energy, such as generation of moisture content for a humidifier, heating of a compressed air, etc. is recovered from exhaust gas from a turbine, it is possible to achieve a further improvement in power generating efficiency.
By the way, a gas turbine equipment of this kind is provided with a feed water system for circulation and utilization of water used in a humidifier for humidification of a compressed air. Since the water circulating in the system is in contact with a compressed air in the humidifier to contain oxygen, it is required that a high corrosion-resisting material (for example, stainless steel) be used in a location, through which feed water containing oxygen flows. In a technology for an improvement in this matter, feed water is reduced in pressure by a vacuum deaerator to create a saturated state, so that the feed water is decreased in dissolved oxygen concentration (that is, oxygen is degassed) (see JP-A-9-264158, etc.)
By the way, since feed water is generally decreased according to an amount used for humidification of a compressed air in a humidifier of a high humidity gas turbine equipment, it is necessary to appropriately supply makeup water. Accordingly, it is demanded to make use of that makeup water, which does not contain oxygen, from the view point of protecting a feed water system against corrosion. However, the technology described above makes no reference to a mechanism for deaeration of makeup water. Also, it can be pointed out that in a vacuum deaerator as in the technology described above, only reduction in pressure of feed water results in an unfavorable deaerating efficiency because of limitation in gas-liquid contact area.